Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!uunet!cbmvax!hood
From: hood@cbmvax.commodore.com (Scott Hood)
Newsgroups: comp.sys.amiga.tech
Subject: Re: COMMODORE PLEASE READ Re: A3000 and a genlock
Keywords: A3000 genlock
Message-ID: <13642@cbmvax.commodore.com>
Date: 6 Aug 90 17:33:16 GMT
References: <19027@well.sf.ca.us> <14297@venera.isi.edu> <1166@tardis.Tymnet.COM>
Reply-To: hood@cbmvax (Scott Hood)
Organization: Commodore, West Chester, PA
Lines: 46

In article <1166@tardis.Tymnet.COM> jms@tardis.Tymnet.COM (Joe Smith) writes:
>In article <14297@venera.isi.edu> schur@venera.isi.edu (Sean Schur) writes:
>>I did read the manual and am aware that you need to disable the VDE, so that
>>isn't the problem. 
>
>My manual says the exact opposite.  One page C-5 of "Introducing the Amiga
>3000", it says "To use the Display Enhancer with an external genlock, simply
>connect the genlock to the Amiga's 23 pin video port, and flip the Display
>Enhancer mode switch DOWN (to the Enable mode position)."
>
>I have found with the Mimetic's AmiGen attached, the 1950 monitor works only
>when the VD is providing a 31KHz signal (enabled).  When the Mode switch is
>UP (disabled) while the AmiGen is attached, the resultant 15KHz signal is
>completely unviewable.  (It looks to have totally random horizontal sync).
>
>With a good quality video signal going into the AmiGen, I get the same quality
>output as I did with the A2000, and at the same time the A1950 is displaying
>the VGA signal perfectly.  However, with a poor quality signal input to the
>AmiGen causes glitches on the A1950.  In particular, the locally generated
>video signal on the Weather Channel (where it shows the local temp and
>barometer readings on a solid-color background) is really bad.  The genlock
>and/or Display Enhancer loses sync on almost every line of text.  And after
>going through the descrambler, HBO's signal sometimes causes vertical
>blanking to extend 3/4th down the screen.
>
>One more thing: I had to shave off part of the side of the VGA connector
>because it was pressing up against the side of the AmiGen's case.
>-- 
>Joe Smith (408)922-6220 | SMTP: jms@tardis.tymnet.com or jms@gemini.tymnet.com
>BT Tymnet Tech Services | UUCP: ...!{ames,pyramid}!oliveb!tymix!tardis!jms
>PO Box 49019, MS-C41    | BIX: smithjoe | 12 PDP-10s still running! "POPJ P,"
>San Jose, CA 95161-9019 | humorous dislaimer: "My Amiga speaks for me."

One thing that you may wish to also try when using a genlock with the
Display Enhancer is if the 31Khz output is tearing and the output from
the genlock is not, try slightly adjusting (in quarter turn intervals)
the fine tuning control using the supplied plastic alignment tool.  This
may help you to get a stable image with your Amigen or other genlock.

Scott Hood

-- 
--
Scott Hood, Hardware Design Engineer (A3000 Crew),  Commodore-Amiga, Inc.
   {uunet|pyramid|rutgers}!cbmvax!hood   hood@cbmvax.cbm.commodore.com
  "The views expressed here are not necessarily those of my employer!"